latticeParseFormula         package:lattice         R Documentation

_P_a_r_s_e _T_r_e_l_l_i_s _f_o_r_m_u_l_a

_D_e_s_c_r_i_p_t_i_o_n:

     this function is used in trellis functions. Might be useful by
     itself. 'y' and 'g_1,...,g_n' may be missing.

_U_s_a_g_e:

     latticeParseFormula(model, data, dimension = 2)

_A_r_g_u_m_e_n_t_s:

   model: the model/formula to be parsed. This can be in either of two
          possible forms, one for 2d and one for 3d formulas,
          determined by the 'dimension' argument. The 2d formulas are
          of the form 'y~x|g_1*...*g_n', and the 3d formulas are of the
          form 'z~x*y|g_1*...*g_n'. In the first form, 'y' may be
          omitted. The conditioning variables 'g_1, ...,g_n' can be
          omitted in either case. 

    data: the environment/dataset where the variables in the  formula
          are evaluated. By default, the environment where the function
          was called from. 

dimension: dimension of the model, see above

_V_a_l_u_e:

     returns a list with components 'left, right, left.name, 
     right.name, condition' for 2d, and 'left, right.x, right.y,
     left.name, right.x.name, right.y.name, condition' for 3d.

_A_u_t_h_o_r(_s):

     Saikat DebRoy saikat@stat.wisc.edu

_S_e_e _A_l_s_o:

     'xyplot', 'Lattice'

